At present, in a database, a high-speed storage device, for example, a solid state disk (Solid State Disk, SSD) is generally used as a level-2 cache of a main memory. The high-speed storage device may also be called a non-volatile cache. One manner for the database to manage the level-2 cache is to read the cache, which means that non-dirty data in the main memory is placed in the level-2 cache. The data placed in the level-2 cache is called warm data. In order to increase query efficiency, information may be saved in the main memory. The description information is used to describe a correspondence between a location in a disk and a location in the level-2 cache of data. Through the description information, the data may be read into the main memory again directly from the level-2 cache and does not need to be read from the disk. When the database is restarted, because the information in the main memory is lost, the description information needs to be re-established.
In the prior art, when the database is restarted, the originally saved data in the level-2 cache of the database are all lost. Data needs to be preheated again. That is, a data block needs to be read from the disk to the main memory again, transferred from the main memory to the level-2 cache, and description information needs to be established in the main memory again. Such process of reading data and establishing description information again in the prior art takes a long time.